Patent drawing - for C. P. Fest's Air Ship Public domain image

Famous patent drawings from The National Archives, Washington DC There are many famous patent drawings from a wide range of inventors and inventions. Some notable examples include: The light bulb: Thomas Edison's patent for the light bulb, which was filed in 1879, included detailed drawings of the bulb's design and construction. The phonograph: Edison's patent for the phonograph, which was filed in 1877, included drawings of the device's components, including the cylinder and the needle. The motion picture camera: Edison's patent for the kinetograph, which was filed in 1891, included drawings of the camera's mechanisms and components, such as the rotating lenses and the film roll. The airplane: The Wright brothers' patent for their airplane, which was filed in 1906, included detailed drawings of the aircraft's design and construction, including its wings, fuselage, and propeller. The telephone: Alexander Graham Bell's patent for the telephone, which was filed in 1876, included drawings of the device's components, such as the transmitter and receiver, as well as a diagram of the electrical circuit. These are just a few examples of famous patent drawings. Many other inventors and inventions have also been represented in detailed drawings in their patent applications.

The main types of airship are non-rigid, semi-rigid, and rigid. Non-rigid airships, often called "blimps", rely on internal pressure to maintain the shape of the airship. Semi-rigid airships maintain the envelope shape by internal pressure but have a supporting structure. Rigid airships have an outer structural framework which maintains the shape and carries all structural loads, while the lifting gas is contained in internal gas bags or cells. Rigid airships were first flown by Count Zeppelin and the vast majority of rigid airships built were manufactured by the firm he founded. As a result, all rigid airships are sometimes called zeppelins. In early dirigibles, the lifting gas used was hydrogen, due to its high lifting capacity and ready availability. Helium gas has almost the same lifting capacity and is not flammable, unlike hydrogen, but is rare and relatively expensive. Airships were most commonly used before the 1940s, but their use decreased over time as their capabilities were surpassed by those of aeroplanes.